Douglas J. Kennett, J.P. Kennett, A. West, C. Mercer, S.S. Que Hee, L. Bement, T.E. Bunch, M. Sellers, and W.S. Wolbach reported their findings in the Science article “Nanodiamonds in the Younger Dryas Boundary Sediment Layer.”
They discovered tiny diamonds, what they called “nanodiamonds,” in sediments at sites from Arizona to South Carolina, within the United States, and Alberta and Manitoba, within Canada.
The nanodiamonds were discovered at a depth that corresponded to being scattered about around 12,900 years ago (plus or minus 100 years).
The team, led by U.S. archeologist Doug Kennett of the Department of Anthropology, University of Oregon, Eugene, states that the discovery of these prolific number of nanodiamonds suggest that they did not originate on Earth.
They claim this because of the extraordinary conditions that would have had to be met for them to be native to our planet.
Instead, the researchers suggest that many comets could have likely impacted the Earth during the beginning of the Younger Dryas interval.
These collisions produced, as they stated in the abstract to their paper, “multiple airbursts and possible surface impacts, with severe repercussions for plants, animals, and humans in North America.”
Page two explains the Younger Dryas period, along with additonal information on the nanodiamond discovery.
The Younger Dryas period, also sometimes commonly called “The Big Freeze,” was a 1,300-year-long interval of time (from 12,800 to 11,500 years ago) in which conditions were cold enough that many animals such as saber-toothed cats and mammoths began extinct in North America
In fact, the researchers found that the layer where the diamonds were found included a “black mat” of “carbon-rich material” that separated the bones of animals and artifacts from the Clovis Indians found before that time-period but not after it.
Kennett explains, "The nanodiamonds that we found at all six locations exist only in sediments associated with the Younger Dryas Boundary layers, not above it or below it.” [Reuters]
The researchers state that the six sites in North America could have experienced one giant explosion or multiple smaller ones, which could have likely caused giant fires and extreme pressures.
Dr. Kennett explains, “These data support the hypothesis that a swarm of comets or carbonaceous chondrites (a type of meteorite) produced multiple air shocks and possible surface impacts at 12,900 (years ago).” [Reuters]
The Reuters article went on to explain, “The heat and pressure could have melted part of the Greenland ice sheet, causing currents to change and affecting climate. Any impacts would have kicked up dust that would have shrouded the sun and lowered temperatures, endangering plants and animals.”
Kennett concluded, "These discoveries provide strong evidence for a cosmic impact event at approximately 12,900 years ago that would have had enormous environmental consequences for plants, animals and humans across North America."